Network configuration

There are 2 possible ways you can configure your setup. You can either configure the network in the way that the client can autodiscover the exam server, or configure the clients to access a fixed IP-address. The client setup can be found here.

Autodiscovery of the exam server

For this to work, you need to be able to discover the exam server via Bonjour. Therefore DNS Service Discovery (DNS-SD) must be allowed in the network. It is necessary to strictly allow this in your network. If you use a wireless network as exam network, notice that most accesspoints will disable this by default. If your server sits in another subnet, you have to route the needed ports, according to the Bonjour standard. Bonjour clients will talk via UDP port 5353 and multicast IP-address 224.0.0.251 (IPv4), ff02::fb (IPv6) respectively.

Avahi includes several utilities which help you discover the services running on a network. For example, run

avahi-browse -r --no-db-lookup _http._tcp

to discover services in your network. If your network and server are configured appropriately, you should discover the exam server with the above command.

Exam server with fixed IP-address

This is a more secure setup. To run the exam server in a network, you have to make sure that clients can connect to the server. On the other hand, the server needs to be able to connect to the clients.

This is a list of services and ports that must be allowed:

Connection	Service	Port
Client to Server	http/https	80 for http, 443 for https (by default)
Server to Client	ssh	22 (by default)

If your exam server sits in another subnet than your exam clients, make sure to disable Network address translation in the configuration of the router. This is necessary because the server detects the clients IP-address (which is then used in remote backup) over the HTTP headers and/or $_SERVER environment variables provided by the webserver. With NAT enabled the header would contain the IP-address of the routing device instead.